214 U.S. NATIONAL MUSEUM BULLETIN 23 7 part i 



nesting material and carrying it into a 60-foot white birch that stood 

 in a fairly open spruce and maple glade near St. Charles de Mandeville, 

 Cont6 Berthier. The nest was about 30 feet up and the female 

 seemed to be doing all the nest-building. The male, however, "ob- 

 served her actions with obvious interest, * * * supervising with 

 care and staying close at all times." 



Evening grosbeak nests have three outstanding characteristics: 

 They are loosely constructed "stick-nests"; some moss or lichen is wo- 

 ven into the structure; and the cup is not really round (as has been re- 

 ported) but oblong or elliptical. They have been reported in seven 

 species of coniferous trees : Balsam-fir, red spruce, black spruce, white 

 pine, Norway (or red) pine, jack piue, and white cedar. The species 

 has also nested in at least seven species of deciduous trees: 

 Willow, aspen, white (or paper) birch, elm. Saskatoon (Amelanchier), 

 and in hard and soft maples. One nesting was in an orchard. 



Eggs. — The evening grosbeak lays from two to five eggs in a set, 

 usually three or four. The eggs are ovate or, rarely, pointed ovate, 

 thin shelled, and of smooth texture with little gloss. The ground color 

 is usually deposited as a clear blue or bright blue-green, which during 

 incubation changes to "pale blue-green" or "pale glaucous-green." 

 They are blotched and spotted, particularly at the larger end, with 

 "olive-brown," "lilac gray," or "light Quaker drab." Fine pencilled 

 markings in black occur on a number of eggs. One with a "pale 

 glaucous-green" shell was stippled all over with "olive-gray" and "pale 

 mouse gray." The eggs resemble rather strikingly those of the red- 

 winged blackbird. The measurements of 23 eggs average 24.5 by 17.5 ; 

 those showing the four extremes measure 28.0 by 18.0, 26.8 by 19.0, 

 21.0 by 16.0, and 21.0 by 16.0 millkneters. 



Incubation. — One egg is laid each morning until the set (usually of 

 three or four eggs) is complete. Incubation has been observed to 

 start on the second day and is performed by the female alone. There 

 is no record of incubation by the male, and but one observation of a 

 male brooding a 3-day old nestling (H. K. Ivor Journal). At times 

 during the incubation period the male feeds his mate both on and off 

 the nest. 



No data on the length of the incubation period in the wild are 

 available, but we have several measurements from aviary nestings. 

 A. G. Lawrence reported to Mr. Bent periods from 11 to 12 days in 

 his aviary. Paul Kuntz (1939) writes from Winnipeg: "The bird 

 sat steady for twelve days. On the thirteenth two young were 

 hatched." J. H. Fleming (1903) observed in his aviary: "About the 

 16th of July three eggs of a second set were noticed in the nest; one 

 had disappeared before my return, and on the 30th one of the two 

 remaining eggs hatched." The incubation period in this case was at 



